Skeletal disease, serum acid phosphatase

Carcinoma of the prostate is today one of the three most frequent causes of death from neoplastic disease in men in the United States (G4). The early studies of Gutman and his associates (Gil, G12, R6, S30) established that serum acid phosphatase activity was elevated very frequently in patients with metastatic carcinoma of the prostate. It is of interest to consider briefly the uncertainties inherent in the development of this relationship. Skeletal metastases, if sufficiently large, are of course detectable by roentgenographic examination, but smaller ones may not be, and metastases to soft tissues may likewise be undetectable. For example, in 15 cases of metastazing carcinoma reported by Gutman... 

In 1956, Fishman et al. (F2) summed up their experience with a series of 91 cases of proven cancer of the prostate and a total of 1198 patients with other diseases. Of these 91 cases, 32, or 35%, had elevated total serum acid phosphatase activities. This incidence was much lower than that, 85%, reported by Sullivan et al. (S30) in 1942 or the value of 89% reported by Herbert (H5) in 1946 for patients with carcinoma of the prostate and skeletal metastases. These investigators had used the method of Gutman and Gutman (GIO, G14), which was essentially the same method as that employed by Fishman and Lerner (FI) and gave the same ranges of normal values (Table 6). The possibility existed that treated cases had normal total serum phosphatase activities and thus weighted the overall incidence toward a low value. However, the data of Fishman et al. (F2) show that the incidence of total serum acid phosphatase activities in treated cases was 20/52, or 38%, even higher than the incidence 12/39, or 31%, in the untreated cases. 

One female and one male patient had hyperparathyroidism with elevated serum alkaline phosphatase activities and extensive bone changes characteristic of generalized osteitis fibrosa cystica. In both instances, the serum acid phosphatase activity of the serum fell to normal values after removal of the parathyroid adenoma despite transitorily increased serum alkaline phosphatase activity. The fifth patient was a female with osteopetrosis involving the major part of the skeleton. The serum acid phosphatase was 8.7 K.A. units, the highest in the control series— yet the serum alkaline phosphatase was within normal limits. It would appear, therefore, that some patients with skeletal disease may have a slight but definitely elevated serum acid phosphatase activity, at least as determined by the Gutman method (GIO, G14), which cannot be explained by concurrent prostatic carcinoma or by a spillover of alkaline phosphatase activity to a pH of 5.0. 

Table 10 shows the distribution of serum acid phosphatase activities in neoplastic disease other than prostatic cancer. The incidences of elevations were 19% in patients with skeletal metastases 2% in pa-... 

G12. Gutman, A. B., Gutman, E. B., and Robinson, J. N., Determination of serum acid phosphatase activity in differentiating skeletal metastases secondary to prostatic carcinoma from Paget s disease of bone. Amer. J. Cancer 38, 103-108 (1940). 

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